Floats to suspend a mechanical device on the surface of liquid in a basin are fairly well known in the water and wastewater treatment industry. For example, surface mechanical aerators are floated on the surface of water or wastewater to be aerated. Typical surface mechanical aerators are sold by Aqua-Aerobic Systems, Inc. of Rockford, Ill. under the trade names AquaJet® and AquaJet II®. In general, these devices have an aerator mounted to a rigid, typically circular float that must be of sufficient size to generate enough buoyancy to support the aerator equipment. Similarly, surface mechanical mixers are also supported on floats on the surface of water or wastewater in a lagoon or basin. A typical surface mechanical mixer is available from Aqua-Aerobic Systems, Inc. under the trade name AquaDDM®. Like an aerator, a mixer is mounted on a generally circular, solid float. Again, such floats must have fairly large diameters (if circular) so that they generate sufficient buoyancy to support the associated mechanical equipment. The floats are typically moored into place in the desired location so that they do not move during use or otherwise.
Installing aerators, mixers and other mechanical devices and their associated floats is straightforward in open basins. Because the lagoons or basins are open, the size of the mechanical device and associated float does not impede installation or impose a size restriction on the equipment that may be used. Similarly, in new facilities, consideration may be made in advance for the installation, repair and replacement of equipment. However, many existing basins are enclosed in a building or other structure. There is limited ability in such structures to provide access to install new or replacement equipment. Thus, there is a physical limitation on the size of equipment that may be installed in existing enclosed locations, because access through existing roofs, walls and even doors is limited. Accordingly, while it is relatively easy to accommodate installation of equipment in new and open basins, many existing facilities have enclosed basins and have limited access to the interior, making it more difficult to retrofit different devices into the location to accommodate changing needs or requirements.
For example, many drinking water treatment installations or treatment steps are enclosed. In the treatment of drinking water, certain by-products of disinfection, such as trihalomethanes (THMs) are formed. Increasing government regulations require the removal of THMs, which may effectively be done using surface mechanical aeration, the most common form for which is floating aeration. However, because many existing drinking water treatment facilities are enclosed, having roof structures with limited openings available for the introduction of new equipment, traditional and known floats that support aerators and other equipment on the surface of the basin are too large to fit within the available openings of such installations.
Thus, there is a need, particularly in the water and wastewater treatment industry, to provide a float assembly that may fit through a fenestration or other reasonably available or created opening of an enclosed treatment basin, at the same time providing sufficient buoyancy to support the associated equipment such as aerators, mixers and the like.